What's the thing around the tube on my BVM?

[atheistgod1999]

I'm asking because I accidentally broke off one of the tabs holding it in place and I want to know if I weakened something important. Here's a picture (the tab I broke off was going through the hole on the top that's slightly covered up):


Is it some unneeded radiation shielding added due to the FCC? Fudoh, if you're reading this, could you open the top of your 20F1E and take a picture of it?

[Ed Oscuro]

Haha. Don't be like me, opening stuff you never put back together. If it ain't broke, don't fix it. You start to see how expensive this hobby can become, though, if something needs work.

I do believe that's a kind of magnetic shield, though; most radiation in a CRT actually goes out the back and sides as the front glass is heavily shielded. However this is probably mainly to block magnetic fields so these monitors can be stacked and lined up without affecting each other's picture (something PVMs don't do so well).

These designs are pretty redundant and it should hold, if you stop screwing with it.

[ApolloBoy]

I do believe that's a kind of magnetic shield, though

Bingo.

[Guspaz]

Although it's for shielding the CRT from external interference, not the other way around. CRTs are super sensitive to magnetic fields, sometimes even the earth's geomagnetic field is enough to cause problems unless you rotate the monitor.

[atheistgod1999]

Although it's for shielding the CRT from external interference, not the other way around. CRTs are super sensitive to magnetic fields, sometimes even the earth's geomagnetic field is enough to cause problems unless you rotate the monitor.

Are you serious? So if the shield falls off my picture's gonna be horrible? Great, now I just severely damaged a rare, limited supply RGB monitor.

[atheistgod1999]

Haha. Don't be like me, opening stuff you never put back together. If it ain't broke, don't fix it.

I was trying to detach the bezel because I pushed in the tally lamp and wanted to reattach it to the front with glue. I thought the tabs worked like screws and I twisted the one I broke off 90 degrees. The other ones were harder and I couldn't even move them with a screwdriver (look at the scratches in the picture) so I decided to just wait until my dad (who's an electrical engineer) got home because he would show me the correct way to detach it. We got the bezel off and reattached the tally lamp, and last night I figured I should twist the tab back to the way it was originally. As soon as I slightly pulled it, it snapped off. That's the whole story.

[ApolloBoy]

Are you serious? So if the shield falls off my picture's gonna be horrible?

Not unless you stick it near another CRT or unshielded speakers. Plus it's just one tab that broke, I think you're overreacting. Your BVM's just gonna sit so there's no real danger of it falling off.

[Ed Oscuro]

I think you're overreacting.

Basically the only thing that needs to be said. BVMs are pretty sturdy stuff, just losing a tab isn't going to kill it.

But be smart and don't poke around aimlessly inside of your unit.

[gray117]

Yeah... If you're not putting it next to speakers or another monitor that you're turning on or off likely you'd never notice if you took it away.... Dunno these days people may even prefer removing it like doj cases if there was an idea it could limit ventilation over longer periods of operation... Although conversely perhaps helps prevent dust settling on components which can also promote heat build up... So yeah minor detail if you want to agonise, but certainly not something you've ruined it anything like that.

[MKL]

The shield is held by the same four screws as the tube so it's not going to fall off. It also serves the purpose of holding the degaussing coil so removing it is a bad idea. What broke is probably one of the degaussing coil holders but you still have all the others, no big deal.

[mikejmoffitt]

That shield isn't going to cause heat problems as it's near the face of the tube. I'd keep it, as it's just one piece of the BVM that lets it be an excellent reliable monitor, in this case with regards to reducing outside magnetic influence.

[atheistgod1999]

That shield isn't going to cause heat problems as it's near the face of the tube. I'd keep it, as it's just one piece of the BVM that lets it be an excellent reliable monitor, in this case with regards to reducing outside magnetic influence.

I wasn't going to remove it, I just wanted to know if I broke something important.

[cfx]

.

[atheistgod1999]

Is the tab you broke off inside the monitor somewhere now? If so it's a potential electrical short waiting to happen.

yeah it is. It's at the bottom. HOW DO I REMOVE IT? It's plastic though.

[Crafty+Mech]

Very few arcade monitors have that shielding, and they work fine. Just don't run anything that produces a lot of EMI right next to it.

These are CRT monitors we are talking about, not nuclear reactors. The are built to function under a variety of operating conditions.

[Ed Oscuro]

But he doesn't have to worry about EMI because of the shield. Come on, let's not try to confuse the guy further.

The shield is good, the shield is great, don't wipe the shield like a plate...er something something

[MKL]

Very few arcade monitors have that shielding, and they work fine.

Because every tube has an internal shield.

[Crafty+Mech]

My whole point is he is worried about nothing. OP stop obsessing and play your games.

[atheistgod1999]

Is it possible to replace the tab?